Tailoring the d-Band Center over Isomorphism Pyrite Catalyst for Optimized Intrinsic Affinity to Intermediates in Lithium-Oxygen Batteries

Rechargeable lithium-oxygen batteries (LOBs) are regarded as one of the most promising candidates for the next generation of energy storage devices. Nevertheless, the lack of understanding of the relationships between structure, property, and performance of catalysts limits the rational development of efficient cathode catalysts, and therefore, hinders the commercial application of LOBs. Herein, a d-band center regulation strategy is proposed to construct an isomorphism composite of NiS2-CoS2@nitrogen-doped carbon (NiS2-CoS2@NC) as an advanced cathode catalyst for boosting the electrocatalytic activities of LOBs. Density functional theory calculations reveal that the introduction of Ni atoms not only redistributes the internal charges on the isomorphism structure but also modulates the adsorption capacities of the intermediates by tuning the d-band center, thus promoting oxygen reduction reaction/oxygen evolution reaction kinetics and reducing the reaction overpotentials. As expected, NiS2-CoS2@NC catalyzed LOBs present superior electrochemical performance including large initial discharge/charge specific capacity of 14 551/13 563 mAh g(-1), an ultralong cycle life over 490 cycles at a current density of 500 mA g(-1), and excellent rate performance. The insight into the regulation of the adsorption capacity of the catalyst by tailoring its d-band center facilitates the rational construction of efficient electrocatalysts for LOBs and other electrocatalytic systems.